The impact of meditation on the regulation of emotion is perhaps the most salient effect of meditation for the average practitioner. Yet the mechanisms responsible for these alterations are pooriy understood and the consequences of these changes have not been characterized. The purpose of this project is to examine the impact of these two forms of meditation on the neural, biobehavioral and hormonal correlates of emotion regulation among naive practitioners who learn Mindfulness-Based Stress Reduction (MBSR) and among Long-Term Meditators (LTMs). The MBSR group will be compared with our rigorous comparison intervention, the Health Enhancement Program (HEP) and to Wait List (WL) controls. Both of the active groups will be administered booster training following the completion of the 8-week course to maximize consolidation of learning and increase the amount of practice. These groups will be tested before and after training. The LTMs will be studied on three occasions: once with no practice period prior to testing, once after an intensive day of MM practice and once after an intensive day of LKM-CO practice. Participants will be tested on an emotion regulation task in the scanner during which four conditions will be randomly interspersed across blocks: MM, LKM-CO, relaxation and listening to music. The task will consist of the presentation of pictures depicting human suffering (negative) or human flourishing (positive) while participants engage in one of the four regulatory conditions. Facial electromyography (fEMG) will be recorded from corrugator and zygomatic muscle regions in the scanner to provide real-time online objective measures of emotion during the regulation conditions. Saliva will be collected for three consecutive days, three times/day just prior to each lab visit to provide measures of Cortisol and total Cortisol output to relate to the fMRI measures. We predict that MM will primarily impact fronto-amgydala circutiry and LKM-CO will impact fronto-striatal circuitry and that these neural changes will have downstream biobehavioral effects on reports of daily mood, Cortisol and immune measures collected in this and the other two CERC projects. RELEVANCE (See instructions): This project will provide unique new information on the mechanisms by which two of the most commonly taught meditation practices work. The downstream biobehavioral consequences of these practices will be examined and relations between practice time, changes in brain function and alterations in behavior and peripheral biology will be explored in analyses examining relations among measures across projects.